Humidifiers are devices that boost the level of moisture — or humidity — in the air by releasing water vapor or steam.
The natural humidity level in the air varies by weather: typically, in the Northern Hemisphere, winter air is dryer and summer air is moister. Higher humidity has many health benefits, from keeping skin healthy to reducing symptoms of asthma and allergies.
Humidifiers can be a great way to increase humidity, especially during dryer seasons. Here are some health benefits of humidifiers:
1. Reduces the spread of germs
Humidifiers can help prevent you from getting sick by adding moisture to the air. In particular, research has found that humidifiers can help protect against the flu.
A 2013 study found that if indoor humidity levels are less than 23%, influenza’s infectivity rate — or its ability to infect others via respiratory air droplets — is between 70% and 77%. If indoor humidity is kept above 43%, the infectivity rate is much lower, between 14% and 22%.
This is because the influenza virus survives better in drier conditions.A 2010 study evaluated the impact of a humidifier during winter months and found that a portable humidifier decreased influenza virus survival by 17.5% to 31.6%.
2. Prevents dry skin
Dry air pulls moisture from the skin, making it feel itchy and irritated, says Debra Jaliman，MD,an assistant clinical professor of dermatology at Icahn School of Medicine at Mount Sinai in New York.
Humidifiers can counter this effect by increasing moisture in the air to help avoid discomfort and “get your skin glowing again,” Jaliman says.
For example, a small 2008 study in a Japanese hospital found that using a humidifier in winter boosted humidity from 32.8% to 43.9% and relieved dry and itchy skin symptoms among staff.
3. Relieves asthma and allergy symptoms
Humidifiers can help with allergy and asthma symptoms by soothing tissues in the nose and throat, says Andrew Stiehm，MD,a pulmonologist with Allina Health’s United Lung and Sleep Centre in Saint Paul, MN.
This can help relieve symptoms like:
- A dry and itchy throat
- Runny nose
- Coughing
- Nose bleeds
- Sinus congestion
However, too much humidity can cause dust mites and mold to spread. Therefore, people with these indoor allergies should clean their humidifiers regularly and monitor humidity levels so they don’t exceed 50%.
4. May loosen congestion
Humidifiers can also loosen congestion by moistening the nasal passage. When you get sick, the cells lining your respiratory tract generate more mucus, Stiehm says. When the mucus dries, it can become “sticky” — which makes it hard to blow or cough.
Increasing air moisture can make it easier for you to expel the mucus when coughing or blowing your nose, by preventing it from drying, Stiehm says.
Humidifiers are often added to continuous positive airway pressure treatment (CPAP) machines used on sleep apnea patients. That’s because CPAP blows dry air up your nose, which can increase congestion. A small 2010 study found that using heated humidification on sleep apnea patients receiving CPAP treatment helped reduce symptoms of a stuffy nose.
5. Alleviates snoring
Humidifiers can also reduce snoring from nasal congestion by helping loosen mucus blocking your airway. In general, “the more open your airways, the less snoring,” Stiehm says. Snoring is common among people with sleep apnea. Being a man, being overweight, having nasal problems, and drinking alcohol can also increase your risk for snoring.
